SX-450 rebuild list

slayer44

Well-Known Member
Does anyone have a current re-cap list for the AWK-060B board?...The database has an incomplete BOM and I need a more up to date list using modern Fairchild transistors. I have searched and searched the threads and can't find any substitutes for the drivers (other than try this or this). I would really appreciate some input. Thanks in advance.
 
Does anyone have a current re-cap list for the AWK-060B board?...The database has an incomplete BOM and I need a more up to date list using modern Fairchild transistors. I have searched and searched the threads and can't find any substitutes for the drivers (other than try this or this). I would really appreciate some input. Thanks in advance.

(No offense) but unless there's something terribly wrong with the unit I wouldn't bother replacing the transistors on a bottom of the line receiver. Replacing transistors espeicially output transistors makes very little difference. If you really must I think the MJE15032G will be a good sub Mouser has them in stock.
 
And if you need Q207 to Q210 I would reccomend the KSA1220A and KSC2690A both of which mouser also has in stock. :)
 
No offense taken, but I had a massive failure and split left channel drivers and outputs as well as several burned out resistors, so I think my request is valid. As to bottom line, this is the baby of one of my friends who purchased it new when he had nothing, so he want's it back to keep it in the family.
 
No offense taken, but I had a massive failure and split left channel drivers and outputs as well as several burned out resistors, so I think my request is valid. As to bottom line, this is the baby of one of my friends who purchased it new when he had nothing, so he want's it back to keep it in the family.

Understandable. May be worth replacing the input diff pair, they're known for causing issues. 2SA725's easily replaced with a matched pair of KSA992F's with their emitters soldered together and thermally bonded using heatshrink.
 
Oops, ignore me I'm being a dope, thinking of the 2SA798 used in other Pioneers, the 725's are normal TO-92 transistors. Just replace with regular KSA992F's
 
Okay....next question. Where do the Collectors/Bases go from each?...this is really helpful.

As they are, they're normally just a inline package. Here's a pic of a 798.

s-l300.jpg

Not relevent to the SX-450 but good information to have handy in the future I suppose... It's been a long day..
 
Phew!...good to go there. Already have this bit of info from another post...but your ganging for the 798 is good to know for future reference. I saw somewhere that TIP41C's could also be used for the outputs. Do you know if that is correct?
 
Phew!...good to go there. Already have this bit of info from another post...but your ganging for the 798 is good to know for future reference. I saw somewhere that TIP41C's could also be used for the outputs. Do you know if that is correct?

I've used them as replacements in power supply applications but not as a replacement for outputs as far as I remember. If you have them on hand give them a try.

Haven't run across a 798 in my travels yet, but I am sure I'll see one. :)

A lot of mid to late 70s gear used them. I have a Pioneer SX-750 and a Mitsubishi DA-U310 that used 'em.
 
Okay, Thank you very much Eastham...I think I have enough to go forward. I will try the TIP41's with the DBT on and let you know if they work or not. Take care and good night.
 
The TIP41Cs could be a little light on current gain, but are reasonable to try. A more direct replacement is the KSD526Y. The MJE15032G is overkill, but will work just great.
 
Thanks Watthour...I will go with the MJE15032G's...I like overkill (and want this to last another 40 years!)...thanks for all the input guys.
 
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